Display panels used in cell phone products at present are mainly thin film transistor liquid crystal displays (TFT-LCDs). Notebooks, monitors, televisions and other products mostly adopt display panels for indoor use, and thus TFT-LCD products of transmissive type are mostly used. However, the cell phone products are not only used indoors but also used outdoors. In order to meet the demand characteristics of indoor/outdoor dual-usage, a transflective technology is often employed. The transflective technology refers to such a technology that one portion of a pixel is a reflective region, and another portion of it is a transmissive region. Display panels prepared in the transflective technology are suitable for either indoor or outdoor usage.
As shown in FIG. 1, an array substrate of an existing transflective liquid crystal display panel comprises a glass substrate 1, on which a TFT device 8 is provided. The TFT device 8 includes a gate electrode 2, a source electrode 81 and a drain electrode 82, between the source electrode 81 and the drain electrode 82, there is provided an active layer 4, and on the source electrode 81 and the drain electrode 82, there are formed a passivation layer 7 and a pixel electrode layer 15. On a part of the pixel electrode layer 15, there is a resin layer 9, and on a surface of the resin layer 9, there is formed an embossing structure 52 with a metal layer possessing a reflective property coated thereon. The resin layer 9 and the metal layer possessing the reflective property form a reflective layer 5 capable of reflecting external light. A region in another part of the pixel electrode layer 15 without the coated resin layer 9 forms a transmissive region. A reflective surface formed by the embossing structure 52 has a good diffusion property, allows light to be reflected to liquid crystals and gives rise to a wider angle scope in front of the display screen.
FIG. 2 is a schematic view showing the state of liquid crystal molecules of the display panel shown in FIG. 1 in the case of white grayscale, and FIG. 3 is a schematic view showing the state of liquid crystal molecules of the display panel shown in FIG. 1 when they are changed from the state of white grayscale shown in FIG. 2 into a medium grayscale;
The display panel in FIG. 2 and the display panel in FIG. 3 each include an array substrate 21 and a color filter (CF) substrate 22 that is cell-assembled with the array substrate, and liquid crystals is filled between the array substrate and the CF substrate. When liquid crystal molecules are changed from white grayscale (as shown in FIG. 2) into the medium grayscale (as shown in FIG. 3), the anisotropy of refractivity of liquid crystals becomes larger, and meanwhile the transmittance of light having a longer wavelength passing through red pixels is also increased. Thus, ideal white is not obtained, and a phenomenon of yellowish occurs; that is, a phenomenon of color deviation takes place. This degrades the quality of picture of the display panel. Liquid crystal display panels of total-reflective type suffer from a similar problem.
Grayscale herein generally means that each of sub-pixels shows different levels of brightness. A point on a liquid crystal screen as seen by naked eyes of people, i.e., a pixel consists of three sub-pixels, which are red, green, blue (RGB) sub-pixels. Grayscale represents the deferent levels of brightness from the darkest to the brightest for a picture. The more the intermediate hierarchical levels are, the more delicate the picture effect can be presented. Each pixel on the LCD screen is combined by red, green, and blue sub-pixels at different brightness levels, and eventually different color points are formed. That is to say, the color change of each point on the screen is actually caused by the grayscale change of three RGB sub-pixels constituting this pixel point.